Burglar-alarm lock.



L. F. LOHRENS.

BUHGLAR ALARM LOCK.

APPLICATION FILED APR.1. 1916.

MQ. Patented-Feb. 6, 1917.

2 SHEETS-SHEET l.

Pf l. f' @im L. F. LOHRENS.

BURGLAR ALARM LOCK.

APPLlcATloN flu-:n APR. l. 191e.

1 ,2l4,695. Patented Feb. 6, 1917.

2 SHEETS-SHEET 2.

M az@ Y LOUIS F. LOHRENS, 0F CHICAGO, ILLINOIS.

BURGLAR-ALARM LOCK.

Specification of Letters Patent.

Patented Feb. 6, 1917.

Application led April 1, 1916. Serial No. 88,197.

T0 all whom 'it 'may concern:

Be it known that I, Louis F. LoHRnNs, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Burglar-Alarm Locks, of which the following is a specication.

This invention relates to improvements in alarm devices and more particularly to an alarm associated with a door guard whereby an audible signal is given whenever pressure is exerted on the door, as in an eifort to open it.

Guards which lock the door when in closed position, but by a different adjustment can be adapted to permit the door to be opened a few inches are well known. A common type comprises a fixed part secured to the door, having a button projecting from its end and a rotatable flattened knob projecting from its face, together with a hinged hasp with an elongated slot secured to the casing. When the door is closed the hasp is folded over the front face of the part attached to the doorv and the knob turned, thus locking the device and preventing opening of the door. On the other hand if it is desired to open the door a few inches and still maintain it locked against further opening, it is possible to insert the lmob projecting from the end of the part on the door into the slot in the hasp which then extends at right angles to the frame and permits the door to open a few inches without unlocking it, the knob being limited in its movement by the closed end of the slot in the hasp.

The object of my invention is to combine with such a guard a signal which will give an audible alarm whenever either cf the twov locks are in operation and pressure is exerted on the door, as in an effort to open the same.

Another object of my invention is to provide such an alarm which, after being initiated, even though pressure on the door is withdrawn, will continue to ring for a predetermined length of time.

Another object of my invention is to provide such an alarm in combination with a door guard without in any way interfering with the function performed by the guard.

Still other and further objects will become apparent to those skilled in the art from a consideration of the following description and drawings wherein- Figure 1 is a front elevation of a fragment of a door and casing showing my improved apparatus attached thereto, the hasp being folded over against the door and positioned to lock the door in closed position. Fig. 2 is a vertical sectional view on the line 2-2 of Fig. 1 showing the door partially open and locked against further opening. Fig. 3 is a vertical sectional view through the latch, the bell cover being removed to expose the alarm mechanism. Fig. 4 is a vertical sectional view through the alarm mechanism at the rear of the gea-r train. Fig. 5 is a transverse horizontal sectional view on the line 5 5 of Fig. 3, and; Fig. 6 is a vertical sectional view on the line 6 6 of Fig. 3.

Referring to the drawings the numeral 10 indicates a door adapted to be closed against the casing or jamb' 11. Attached to the jamb of the door is an elongated hasp 12 pivoted, as at 13, to the screw plate 14. An elongated narrow slot 15 extends from near the outer end of the hasp to its pivoted end opening to a recess 15 formed in the screw plate 14 and of somewhat greater width than slot 15. This hasp with its screw fastening plate is of the type commonly supplied with door guards now on the market.

Mounted on the face of the door, adjacent the hasp 12 is a flat base plate 16 carrying on its lower end portion a cup shaped casing 17 within which is positioned the alarm mechanism. The upper end portion of the casing is formed outwardly to provide a rearwardly opening chamber 18 within which the latch is pivoted. The chamber 18 is bounded by a front wall 19, end walls 20, 21, and top and bottom walls 22, 23. Screws 24 take through the plate and secure the same to the door.

The latch member 25 comprises an arm pivoted on a pin 26, which extends through vertically alining apertures 27 in the thickened end wall 21 of the casing. The forward or inner end of the latch 25 is provided with a vertically enlarged head 28 formed on the end of the neck 29 which is suiliciently thin to permit its passage through the slot in the hasp12. The head 28, however, is of a size suliciently large to engage with the sides ot the slot 15 and prevent its removal except when the head 28 is moved into the enlarged opening 15 of thekhasp structure. The opposite end of the latch 25 is provided with an arm 30 which extends through an aperture 31 in the front wall 19 of the chamber 18 and carries on its eXtreme end within the chamber a head 32, the lower edge of which is adapted for contact with the alarm actuating plunger' 33. A. thumb bolt 34 is rotatably mounted on the arm 30 of the latch and projects outwardly for engagement with the slot in the hasp 15. When the thumb bolt 311 is turned to lie in a horizontal plane it is of suiiicient thinness to pass through the opening 15 in the hasp 12 but when it is desired to lock the door in closed position the thumb bolt is given a quarter rotation to position it in a vertical plane as indicated in Fig. 1, thus preventing movement of the hasp about its pivot.

rIhe alarm mechanism comprises a bell cover 50 carried on a spindle 51, by means of which the spring 52 is wound. Connection between the spring spindle and the hammer 53 is provided through a train of gears 54E. The hammer arm 55 is connected with an escapement pawl 56, the operation of which causes vibration of the hammer.. The bell actuating plunger 33 is slidable in the bottom wall 23 of the chamber 18 and carries at its lower end a pin 57 which projects forwardly to underlie a portion of the hammer arm 55. A leaf spring 58 is riveted to the casing, as at 59, its opposite end being secured to the lower end of the alarm release plunger 33. When held in its uppermost position the pin 57 engages the hammer arm and prevents its operation. Depression of the release plunger 33 by engagement oi the latch head 32 with its beveled off upper end 60 releases the hammer arm and permits operation of the bell. In order to insure the ringing of the bell for a predetermined length of time, I have secured to the spindle 51 a plurality, in this instance three, of radiating arms 61, on the end of each of which is 'formed a rounded ci" nub 62 adapted for engagement with a cam like projection 63 on the spring 58. Operation of the plunger 33vwill permit the initiation of the signal, the nub 62 passing from engagement with the springy permitting the same to bend inwardlyy to the dotted line position shown in Fig. 4, maintaining ythe pin 57 out of engagement with the hammer arm, so that should pressure on the upper end oit' plunger 33 be released the signal will continue to ring until the next succeeding arm 61 comes into engagement with the spring 63 and cams it outwardly, again locking the hammer arm.

Whereas I have illustrated and described a single embodiment of my invention it is obvious that various changes may be made therein without departing from the lspirit and scope thereof.

Having described my invention, what I claim is 1. The combination with a door guard comprising a pivotally mounted slotted hasp member and pivotally mounted latch member adapted toengage the slot in the hasp, one member being arranged for attachment to a door and the other to a door casing,`,of an audible signal, and means actuatedA by movement of the latch to initiate operation of the signal. j

2. The combination with a door guard comprising a slotted hasp and latch adapted to be secured to relatively movable parts of the door; of an audible signal adjacent the latch, means connecting the latch withthe part of the door upon which it is mounted and permitting a limited movement of the latch relative thereto, and means connecting the latch and signal whereby movement of the former will initiate operation of the signal. Y

3. The combination with aV door` guard comprising a pivotally mounted slotted hasp; of a pivotally mounted latch member, two projections thereon, either one of which is adapted to engage the slot in the hasp, an audible signal, and means actuated by movement of the latch member to initiate operation of the signal.

4. The combination withv a door guard comprising a pivotally mounted slotted hasp; of a pivotally mounted latch member, a fixedA headed projection extending from the end oit' the latch memberv adjacent the hasp, a flat rotatable thumb bolt projecting from the front of the latch member, both said projection and said thumb bolt being arranged for engagement with the slot in the hasp, an audible signal, and means actuated by movement of the latch member to initiate operation of the signal.

5. The combination with a door guard comprising a pivotally mounted slotted hasp; of a latch member adapted for engagement with the slot in the hasp,; a support for the latch, means connecting the latch with its support to permit limited relative movement with respect to the sup` port, a spring motor bell mounted on the latch support, and a bell release plunger idapted to be actuated on movement of the atch.v

6. The combination with a door guard comprising a pivotally mounted slotted able part of the latch, depresses the plunger 1o hasp; of a latch member adapted for enand releases the bell motor.

gagement with the slot in the hasp, a sup- In testimony whereof I hereunto set my port for the latch, means connecting the hand in the presence of two subscribing latch with its support to permit limited witnesses.

relative movement, a spring motor bell LOUIS F. LOI-IRENS. mounted on the latch support, and a bell In the' presence 0frelease plunger having its free end beveled STANLEY W. COOK,

off whereby engagement therewith byamov- MARY F. ALLEN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

